The BBC was found to have committed a "major breach" of industry standards by failing to disclose that the presenter of a film about the Gaza situation was the child of a Hamas representative, as ruled by regulatory body Ofcom.
An probe by the broadcasting watchdog into Gaza: How to Survive a Warzone has found that the programme was "materially misleading".
The head of the BBC had already issued an apology, saying there had been "a significant failing in relation to truthfulness".
Ofcom has instructed the corporation to air a peak-time announcement about its decisions.
"Given this constitutes a significant violation of our regulations, we are ordering the BBC to transmit a message of our conclusions against it on BBC Two at 21:00, with a timing to be finalised," the regulator stated.
'Possibility to Damage Trust'
The authority's announcement declared: "The inquiry we conducted determined that the documentary's failure to disclose that the narrator's father occupied a post in the Hamas-run authority was significantly deceptive.
"This implied that the viewers did not have vital facts which may have been highly relevant to their evaluation of the voice and the details he provided.
"Credibility is at the center of the bond between a broadcaster and its audience, especially for a national broadcasting corporation such as the public broadcaster.
"This error had the possibility to erode the exceptionally strong amounts of trust that the public would have put in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was withdrawn from the BBC's streaming service in last February after the narrator's family links emerged, and in this past July an broadcaster's internal assessment determined it violated the corporation's content policies on truthfulness.
A representative for the broadcaster commented: "The Ofcom ruling is in line with the findings of the internal assessment, that there was a major oversight in the documentary in relation to the corporation's content standards on accuracy, which aligns with regulation 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we comply with the authority's determination in complete. We will comply with the sanction as soon as the schedule and language are determined."
